Circuit/System Description

A throttle plate actuator is used to achieve high exhaust gas recirculation rates. It increases the pressure difference between exhaust and intake so that the appropriate exhaust quantity can be mixed with the intake air. The ECM transmits the desired angle as a PWM signal to the throttle plate actuator. The throttle plate actuator operates the DC motor to control the throttle plate based on the PWM signal from the ECM.

The throttle body assembly contains a contactless inductive throttle position sensing element that is managed by a customized integrated circuit. The throttle position sensor is mounted within the throttle body assembly and is not serviceable. The ECM supplies the throttle body with a 5 V reference circuit, a low reference circuit, an H-bridge motor directional control circuit, and an asynchronous signal/serial data circuit. The asynchronous signal means communication is only going from the throttle body to the ECM. The throttle body cannot receive data from the ECM over the signal/serial data circuit. The throttle position sensor provides a signal voltage that changes relative to throttle blade angle. The customized integrated circuit translates the voltage based position information into serial data using the Society of Automotive Engineers (SAE) J2716 Single Edge Nibble Transmission (SENT) protocol. The throttle position sensor information is transmitted between the throttle body and the ECM on the signal/serial data circuit.

In the event that the engine control module (ECM) detects the engine speed increases beyond desired control limits. Upon detection, the engine will be shutdown by closing the intake air flow valve and disabling the fuel injectors.